The adjective “derogatory” refers to a prejudice to the honor or reputation in line with Article 6bis of theBerne Convention for the Protection of Literary and Artistic Works (1971).  The term “action” refers to something other than an actual change or interference with the work itself.  It is an action “in relation to” the work.  The term “derogatory action” was added to the Convention at the Brussels Revision in order to cover uses of the work that were prejudicial to the author.  It refers to situations where communication of a work is done in such a manner as to cause the author harm.